I've had a Greenfield kickstand on my touring bike since 1978,tubes are fine(made an aluminum plate for it),hasn't broke yet,holds my bike up fine,even fully loaded.Why reinvent the wheel?

The only thing I've done is added a small plate on the bottom so it doesn't sink in soft stuff.

well the spoke holders are certainly silly, particularly given the usual Derailleur wheel set
uses 3 different lengths of spokes . 2 on the rear, and 1 on the front.

do those spokes fit Any of them?

at least if you fit them on top of the Right side they catch chain slap that may chip the paint.

thread lock the nipples and leave them there , pack the actual spare spokes in your panniers.

tape them to the stiffener panel, rear bag gets the appropriate length for its side.

In my experience there is enough range in the length of thread in the nipple to use the spares on either side of the rear wheel.

Spares are typically the size of the drive side rear where 95% of broken spokes occur.

Still, when I needed to replace a non drive side spoke due to a piece of road debris getting into the spokes, the spare worked fine even though there were threads showing due to the fact that it was not the optimum length.

Front wheel spokes are seldom a problem, but on my bike they are pretty close to the same length as drive side rear ones.

Bottom line... One size will get me going as a replacement for any of the three sizes in a pinch. I am inclined to put the correct size in later when it is convenient, but would be in no rush to do so.

Well at least coordinate the spares and the wheels ..

.. as I understand part of the problems with the Spanish Armada
was they put field cannons on the ships, cannons of all sort of different sizes,
and failed to get sufficient cannon balls on board the right ships of the appropriate sizes for the cannons..

Plus they had this hand to hand combat image , swashbuckling machismo ,
after boarding the English ships, so didn't use the cannons much.